Sociality In Bees


The term 'sociality' describes a broad spectrum of behaviours in bees.  It ranges from non-social, solitary species, through to species which share entrances to individual nest chambers, and finally to advanced social organisations consisting of very large colonies with many thousands of members.

Assigning bees to one particular category can be difficult, especially because bee species from the same genus may nevertheless vary in their degree of sociality.

Levels of Sociality In Bees

In 2021, work by Da Silva1 [citing Cowan (1991), Wilson, (1971); Michener, (1974); Eickwort, (1981)] provided useful definitions of the different levels of social organizations of the insect order, Hymenoptera as follows:

Broad

Narrow

Presocial:
Females nest alone

Solitary:
Females nest alone and mass provision their nests.  They do not interact with their developing young.

Subsocial:
Females nest alone but interact with their developing larvae.  Females may overlap with their adult daughters.

Parasocial:
Females of the same generation interact on
the same nest.

Communal:
Each female builds, oviposits in, and provisions her own cells. [For example, an egg-laying female shares a nest entrance with other fertile females, but once underground, they behave as solitary species].

Quasisocial:
All females cooperate in building and provisioning brood cells, and all females oviposit.

Semisocial:
Some females lay most or all of the eggs. Other females with limited egg-laying opportunities are relegated to foraging, nest building and caring for the young.

Eusocial:
Multiple females cooperate
in nesting and exhibit reproductive division
of labor and there is an
overlap of generations
so that adult offspring assist their mother.

Primitively eusocial:
Colonies are small and short-lived, and morphological differences between reproductive and non-reproductive females are minimal or non-existent.

Advanced eusocial:
Colonies are large and complex and often long-lived.  Reproductive castes are often morphologically distinct from non-reproductive castes.

Note that all bees exhibiting social behaviour fit into the category of 'social', but the term 'social bee' can be further divided into different forms of sociality.

For further information, see my page about eusociality.

Examples of bees within the different forms of sociality (solitary, communal, eusocial bees and so on)

Within his paper, Da Silva further assigned a number of bee species to their specific group within the above defined sociality definitions.  

It's interesting that many bees which tend to be labelled as 'solitary' actually demonstrate at least some form of sociality. 

Furthermore, a whole genus cannot be assigned to one definition of sociality. It's apparent that the behaviours of each specific species needs to be considered.

It is perhaps fair to note that species are sometimes assigned to a particular genus at discovery, only to be switched to a different genus later, which can even result in a name change. 

In a similar fashion, as investigation into bees develops further, the ways in which we assess them may change as our knowledge bank increases in depth and vigor.

It is also the case that scientists may not always agree about how bees are classified.

It is beyond the scope of this page to list every species mentioned, however, for illustrative purposes, some examples mentioned by Da Silva are as follows:

Examples Of Solitary Bees

Lassioglossum occidens
Lassioglossum leucozonium
Lassioglossum zonulum
Centris rhodopus
Centris tarsata
Centris rufosuffusa
Epicharis nigrita
Epicharis metatarsalis
Eucera nigrilabris
Tetrapedia rugulosa
Melissodes druriellus

Examples Of Subsocial Bees

Close-up of an Augochlora pura metallic green sweat bee resting on a leafAugochlora pura - subsocial species

Ceratina flavipes
Ceratina chalybea
Xylocopa torrida
Xylcopa flavorufa
Lassioglossum nupricola
Lassioglossum opacum
Augochlora pura

Examples Of Communal Bees

Euglossa nigrita
Euglossa chapioni
Euglossa hyacinthina
Manuelia postica
Lassioglossum lusorium
Agepostemon texanus
Agepostemon angelicus
Agepostemon virescens
Agepostemon nasutus


Examples Of Quasisocial Bees

Epicharis rustica
Caenohalictus eberhardorum

Examples Of Semisocial Bees

Xylocopa virginica foraging on a pink flower, side viewXylocopa virginica - semisocial species

Xylocopa virginica
Xylocopa nigrita
Ceratina australensis
Augochloropsis sumptuosa
Lassioglossum sordidum

Examples Of Primitively Eusocial Bees

Orange-legged furrow bee, Halictus rubicundus on devil's-bit scabious, Succisa pratensisHalictus rubicundus a primitively eusocial species

Ceratina japonica
Ceratina calcarata
Euglossa cordata
Euglossa townsendi
Euglossa melanotricha
Bombus hypnorum
Bombus jonellus
Bombus atratus
Bombus pensylvanicus
Bombus polaris
Bombus nevadensis
Bombus terrestris
Xylocopa pubescens
Xylocopa suspecta
Xylocopa frontalis
Lassioglossum albipes
Lassioglossum tenax
Lassioglossumopacum
Halictus sexcinctus
Halictus rubicundus
Halictus confusus
Halictus tumulorum
Halictus fulvipes
Halictus scabiosae
Augochlora aurata
Augochloropsis iris


Examples Of Advanced Eusocial Bees

Melipona quadrifasciata, social species that live in several regions of Brazil.Melipona quadrifasciata - eusocial species

Apis mellifera
Apis florea
Apis dorsata
Apis cerana
Melipona quadrifasciata
Melipona scutelaris
Liotrigona medecassa

Bees Of The World - Book Review

Bees Of The World by Laurence Packer book cover featuring coloured images of bees

Reference

1. da Silva J (2021) Life History and the Transitions to Eusociality in the Hymenoptera. Front. Ecol. Evol. 9:727124. doi: 10.3389/fevo.2021.727124

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leafcutter bee on sweet pea plant sweet peas for bees